Publication Date

5-2016

Date of Final Oral Examination (Defense)

3-10-2016

Type of Culminating Activity

Thesis

Degree Title

Master of Science in Chemistry

Department

Chemistry

Major Advisor

Kenneth A. Cornell, Ph.D.

Advisor

Juliette Tinker, Ph.D.

Advisor

Henry Charlier, Ph.D.

Abstract

Klebsiella pneumoniae is an opportunistic bacterial pathogen that is emerging as a major global threat as an infectious agent. This organism, along with many other pathogens, possesses a broad suite of antibiotic resistances that can make treatment exceedingly difficult. As such, the impetus for creating novel antibiotics is at an all-time high despite the fact that pharmaceutical investment into drug development is at an all-time low. S-adenosylmethionine (SAM) is a universally utilized metabolite involved in a wide array of biosynthetic processes, and whose products are catabolized by a different set of enzymes in mammals than used by many bacteria, protozoa, and plants. This divergence provides two specific targets for enzymatic inhibition in K. pneumoniae: 5’-Methylthioadenosine/S-adenosylhomocysteine Nucleosidase (MTN) and 5-Methylthioribose Kinase (MTRK). In order to examine the potential effects of drugs targeting these enzymes, recombinant proteins from K. pneumoniae were isolated and purified, and a profile of their respective kinetic activities were determined. The MTRK enzyme was identified as using an ordered sequential mechanism, and shows preferential binding towards substrate analogs with hydrophobic 5-alkylthio substitutions. In addition, binding affinities of transition state-analogs and novel non-nucleoside small molecule inhibitors of MTN were quantified. Finally, the effects of MTN inhibitors on K. pneumoniae whole-cell growth, and gene expression were assessed. A number of the inhibitors demonstrated strong affinities for the MTN enzyme and induced alterations in cellular growth, autoinducer response, and the expression of genes associated with virulence.

Available for download on Tuesday, May 01, 2018

Included in

Biochemistry Commons

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